scythe

Type-safe database access code is generated by compiling annotated SQL queries with comment annotations like @name and @returns into ready-to-use language-specific structs and functions. This eliminates manual boilerplate and prevents schema mismatches by validating queries before generation.

SQL code generation supports multiple language backends including Rust sqlx, TypeScript pg, and Python asyncpg. You select the appropriate backend for your target language and database engine in the scythe.toml configuration file to generate accurate type mappings.

Annotated SQL linting and formatting works by applying a 93-rule linter, including sqruff rules, to catch SQL issues early and enforce consistent formatting. These checks can be wired into developer workflows via pre-commit hooks and CI pipelines to validate queries without generating code.

Migrating from sqlc to a multi-language SQL code generator involves configuring the new backend in scythe.toml and re-annotating queries. This allows you to validate existing queries, enforce engine compatibility, and generate language-specific structs with correct nullability and overridden types across different database engines.

Nullability and type overrides for generated database structs are handled through configurable backends and type mappings defined in scythe.toml. The compiler applies these overrides during generation to ensure language-specific functions and structs reflect the correct null constraints and custom types.

Pre-generation validation fails for mismatched SQL schemas because the compiler enforces engine and backend compatibility while parsing annotated SQL. It applies linting rules to catch structural issues early, ensuring that fragile query code and schema mismatches are resolved before generating the access layer.